The 24-hour dexamethasone suppression test in a clinical setting: relationship to diagnosis, symptoms, and response to treatment.

Of 54 male psychiatric patients undergoing dexamethasone suppression tests in a clinical setting, 40% of those with a major depressive disorder showed escape from suppression over the 24 hours after dexamethasone administration, while all of the patients with schizophrenia, neurosis, alcoholism,and drug abuse showed normal pituitary-adrenal suppression. Only 10% of the depressed patients showed resistance to suppression 8 hours after dexamethasone administration. There was no difference between depressed patients who did and did not show escape from suppression in type of previous episodes, family history, symptoms, or medication. However, those who showed escape tended to respond better to treatment and to be rated as having a more severe depression. The theoretical and clinical implications of these findings are not yet clear.